THIELMANN, JOHANN ADOLF, Freiherr von (1765-1824), Prussian cavalry soldier, was born at Dresden. Entering the Saxon cavalry in 1782, he saw service against the French in the Revolutionary Wars and in the Jena campaign. When, after the disaster of Jena, Saxony allied herself with her conqueror, Thielmann accompanied the Saxon contingent which fought at the siege of Danzig and at Friedland. In 1809, as colonel of a Free-Corps, he opposed the advance of the Austrians into Saxony, and was rewarded for his services with the grade of major-general, further promotion to lieutenant-general following in 1810. As commander of the Saxon Heavy Cavalry Brigade he took part in the advance on Moscow two years later, and his conduct at Borodino attracted the attention of Napoleon, who took Thielmann into his own suite. His own sovereign at the same time made him Freiherr. In the war of Liberation Thielmann took a prominent part; as governor of Torgau, by his king's orders he at first observed the strictest neutrality, but on receipt of an order to hand over the fortress to the French he resigned his command and, accompanied by his staff officer Aster, joined the allies. As a Russian general he was employed in reorganizing the Saxon army after Leipzig, and in 1814 he commanded the Saxon corps operating in the Low Countries. Early in the following year he became a lieutenant-general in the Prussian service, and in command of the 3rd army corps he took part in the Waterloo campaign. From the field of Ligny he retired with the rest of Blücher's army on Wavre, and when the other corps marched towards Waterloo, Thielmann covered this movement against Grouchy, fighting the spirited action of Wavre (June 18-19). He was later a corps commander at Münster and at Coblenz, and at the latter place he died in 1824.